Recently, the technique for arranging high-sensitivity pixels and low-sensitivity pixels adjacent to one another in an imaging region in a solid-state imaging device such as a CCD image sensor or CMOS image sensor to expand the dynamic range is proposed. In this device, the high-sensitivity pixel and low-sensitivity pixel of the same photodiode size are arranged in a single unit cell. Further, a micro-lens with a large area is arranged on the high-sensitivity pixel and a micro-lens with a small area is arranged on the low-sensitivity pixel.
However, in this type of device, the following problem occurs. That is, since an amount of signal charges generated at the low-illumination time (dark time) is small, the photodiode is not saturated. However, since an incident light amount is large at the high-illumination time (bright time), there occurs a strong possibility that not only the photodiode of the high-sensitivity pixel but also the photodiode of the low-sensitivity pixel will be saturated. Further, saturation of the low-sensitivity pixel becomes a factor to lower the dynamic range.